How can I block specific websites from being accessible on my computer...?

Question

And if I want to make them accessible again, what do I do?

Answer 1

You can add them to or remove them from your "hosts" file. You will most likely find the "hosts" file in the c:\windows\system32\drivers\etc\ folder. Open it with a simple text editor like "Edit" and add a new line for each website you would like to block. Here's an example of what the line should look like:

0.0.0.0 ad.doubleclick.net

Get more info ont the subject here: http://en.wikipedia.org/wiki/Hosts_file

Answer 2

if you want to block any site.......just copy the web address of that site .then go to tools option in internet explorer & click on "internet options." go in security tab on the top and then click on "restricted sites". below that there is an option called "sites"
just click on "sites" and then paste your website ame under the category "add this website under this zone"